BOOST_OVERRIDE is unknown override specifier

[mloskot]

/cc @madmongo1

Minimal Working Example

https://godbolt.org/z/x4zx388h6

#include <boost/property_tree/detail/rapidxml.hpp>
int main() {}

Use latest Boost 1.76 and compile with any compiler of your choice. I can not reproduce the problem with Boost 1.75.

Compilation Error

• msvc

error C3646: 'BOOST_OVERRIDE': unknown override specifier

• clang

  /opt/compiler-explorer/libs/boost_1_76_0/boost/property_tree/detail/rapidxml.hpp:61:41: error: expected ';' at end of declaration list
      const char *what() const throw() BOOST_OVERRIDE
                                      ^

• gcc

  /opt/compiler-explorer/libs/boost_1_76_0/boost/property_tree/detail/rapidxml.hpp:61:40: error: expected ';' at end of member declaration
  61 |         const char *what() const throw() BOOST_OVERRIDE
    |                                        ^
    |                                         ;
  /opt/compiler-explorer/libs/boost_1_76_0/boost/property_tree/detail/rapidxml.hpp:61:42: error: 'BOOST_OVERRIDE' does not name a type; did you mean 'BOOST_VERIFY'?
  61 |         const char *what() const throw() BOOST_OVERRIDE
    |                                          ^~~~~~~~~~~~~~
    |                                          BOOST_VERIFY

References

It looks like PR #53 from @EugeneZelenko introduced this bug - likely, missing #include <boost/config.hpp>. There seem to be no related test case to check headers are self-contained.